remove file first when overwriting

fixes NatronGitHub/Natron#666

EXR/WriteEXR.cpp

@@ -25,6 +25,7 @@
 #include <memory>
 
 #include "ofxsMacros.h"
+#include "ofxsFileOpen.h"
 
 GCC_DIAG_OFF(deprecated)
 #include <ImfChannelList.h>
@@ -207,6 +208,13 @@ WriteEXRPlugin::encode(const string& filename,
     }
 
     assert(pixelDataNComps);
+
+    // If the file exists (which means "overwrite" was checked), remove it first.
+    // See https://github.com/NatronGitHub/Natron/issues/666
+    if (OFX::exists_utf8( filename.c_str() )) {
+        OFX::remove_utf8( filename.c_str() );
+    }
+
     try {
         int compressionIndex;
         _compression->getValue(compressionIndex);

FFmpeg/WriteFFmpeg.cpp

@@ -77,7 +77,7 @@ extern "C" {
 }
 #include "IOUtility.h"
 #include "ofxsMacros.h"
-
+#include "ofxsFileOpen.h"
 
 #ifdef OFX_IO_USING_OCIO
 #include "GenericOCIO.h"
@@ -3739,6 +3739,12 @@ WriteFFmpegPlugin::beginEncode(const string& filename,
         return;
     }
 
+    // If the file exists (which means "overwrite" was checked), remove it first.
+    // See https://github.com/NatronGitHub/Natron/issues/666
+    if (OFX::exists_utf8( filename.c_str() )) {
+        OFX::remove_utf8( filename.c_str() );
+    }
+
     assert(!_formatContext);
     if (!_formatContext) {
         avformat_alloc_output_context2( &_formatContext, avOutputFormat, nullptr, filename.c_str() );

OIIO/WriteOIIO.cpp

@@ -1391,7 +1391,18 @@ WriteOIIOPlugin::beginEncodeParts(void* user_data,
     }
     } // switch
 
-
+    // If the file exists (which means "overwrite" was checked), remove it first.
+    // See https://github.com/NatronGitHub/Natron/issues/666
+    if (Filesystem::exists(filename)) {
+        string err;
+        bool ok = Filesystem::remove(filename, err);
+        if (!ok) {
+            setPersistentMessage(Message::eMessageError, "", err);
+            throwSuiteStatusException(kOfxStatFailed);
+        }
+    }
+    // Some formats only support opening all subimages at once.
+    // See https://openimageio.readthedocs.io/en/stable/imageoutput.html
     if ( !data->output->open( filename, data->specs.size(), &data->specs.front() ) ) {
         setPersistentMessage( Message::eMessageError, "", data->output->geterror() );
         throwSuiteStatusException(kOfxStatFailed);

PFM/WritePFM.cpp

@@ -164,6 +164,12 @@ WritePFMPlugin::encode(const string& filename,
         return;
     }
 
+    // If the file exists (which means "overwrite" was checked), remove it first.
+    // See https://github.com/NatronGitHub/Natron/issues/666
+    if (OFX::exists_utf8( filename.c_str() )) {
+        OFX::remove_utf8( filename.c_str() );
+    }
+
     std::FILE *const nfile = fopen_utf8(filename.c_str(), "wb");
     if (!nfile) {
         setPersistentMessage(Message::eMessageError, "", "Cannot open file \"" + filename + "\"");

PNG/WritePNG.cpp

@@ -717,6 +717,12 @@ WritePNGPlugin::encode(const string& filename,
         return;
     }
 
+    // If the file exists (which means "overwrite" was checked), remove it first.
+    // See https://github.com/NatronGitHub/Natron/issues/666
+    if (OFX::exists_utf8( filename.c_str() )) {
+        OFX::remove_utf8( filename.c_str() );
+    }
+
     png_structp png = NULL;
     png_infop info = NULL;
     FILE* file = NULL;